A longitudinal study of complement clauses and false belief

To examine whether children’s acquisition of perspective-marking language supports development in their ability to reason about mental states, we conducted a longitudinal study testing whether proficiency with complement clauses around age three explained variance in false-belief reasoning six months later. 45 English-speaking 2-and-3-year-olds (23 female, Time 1 age range: 33-41 months) from middle-class families in the North-West of England, took part in the study, which addresses a series of uncertainties in previous studies: We avoided the confound of using complement clauses in the false-belief tests, assessed complement-clause proficiency with a new comprehensive test designed to capture gradual development, and controlled for individual differences in executive functioning that could affect both linguistic and sociocognitive performance. Further, we aimed to disentangle the influence of two aspects of complement-clause acquisition: proficiency with the perspective-marking syntactic structure itself and understanding of the specific mental verbs used in this syntactic structure. To investigate direction of causality, we also tested whether early false-belief reasoning predicted later complement-clause proficiency. The results provide strong support for the hypothesis that complement-clause acquisition promotes development in false-belief reasoning. Proficiency with the general structure of complement-clause constructions and understanding of the specific mental verbs “think” and “know” in 3rd-person complements at Time 1 both contributed uniquely to predicting false-belief performance at Time 2. However, false-belief performance at Time 1 also contributed uniquely to predicting complement-clause proficiency at Time 2. Together, these results indicate a bidirectional relationship between linguistic and sociocognitive development.

本研究旨在探究儿童在获取视角标记语言方面的能力是否对其推理心理状态的能力发展产生影响。为此，我们进行了一项纵向研究，以检验三岁左右时对补足语从句的熟练程度是否可以解释六个月后的错误信念推理中的差异。45名来自英格兰西北部中产阶级家庭的英语母语儿童（其中女性23名，第一次测试时年龄范围为33至41个月）参与了本研究。本研究旨在解决先前研究中的一系列不确定性：我们在错误信念测试中避免了使用补足语从句的混杂因素，通过一项新设计的旨在捕捉渐进发展的全面测试来评估补足语从句的熟练程度，并控制可能影响语言和社会认知表现的执行功能个体差异。此外，我们旨在区分补足语从句习得的两个方面的影响：对视角标记句法结构的熟练程度以及对在此句法结构中使用的特定心理动词的理解。为了探究因果关系的方向，我们还测试了早期错误信念推理是否可以预测后期补足语从句的熟练程度。结果表明，补足语从句的习得促进了错误信念推理的发展。在第一次测试时，对补足语从句构造的一般结构和在第三人称补足语中对“思考”和“知道”等特定心理动词的理解均独特地有助于预测第二次测试时的错误信念表现。然而，第一次测试时的错误信念表现也独特地有助于预测第二次测试时的补足语从句熟练程度。这些结果共同表明了语言与社会认知发展之间的双向关系。